Blasting unit



C. E. BEDENT BLASTING UNIT June 3, 1930.

Filed 001;. 25. 1928 .T Dm m V T mE. MN. E

G ,3 2 z HI 25 units was general several years ago because A Also, explosives containing nitroglycerin,

UNITED STATES yrAriszNr ori-i- 1 mannen 3E. BEDIEN'L or CINCINNATI, onto Y BLnsrINe Umar Application iled October 25, 1928. Serial No. 815,086.

The invention relates to a self-contained Examples of such powders are explosive mixblasting unit particularly adapted for use'in tures containing as a base, chlorate of potassubmarine blasting and under-water blasting sium, nitro-starch, nitrate of ammonia, or 'A in deep, drilled holes containing a column of ssimilar well-known explosive bases. A 5 water. Since, deep holes, generally drilled at pres- 50 During the past three decades, there has ent, are six inches in diameter, the explosive been avcry great increase in the use of high charge of the latter class of explosives vin.- exploslves, known under the general term of serted in such holes extends from the bottom dynamite, due tothe enormously increased upward about half the depthof the hole.

tonnage of crushed stone produced by -quar- 'F or instance, the charge in a hole 50 feet deep ries for use on highways, concrete construewould be approximately feet in depth. lf tion of buildings, streets, bridges, etc. This loaded with gelatin dynamite the Y charge Y has'called for a change-in blasting methods would comprise about 17 cartridges which are suited to increase production'of stone at the 5 inches in diameter and -18 inches longa s quarries. Formerly, the stone was worked These cartridges are individually dropped e@ in shallow ledges with short drill holes of into-thej hole, each cartridge being superiman inch to one and one-half inches in dia'mposed in a Vertical position on the one directeter and a Jfew feet indepth. Dynamite' for 1y underneath. There are sixteen spaces bethis purpose was usually made by inserting tween adjoining cartridges which act as a 20 a plastic explosive in a thin-walled container hindrance to the speed of the wave of detonamade of paper rolled spirally in a tubular tion which passes through-the charge from form and the closure of the ends made by one end to the other.` lt is well known that folding the paper down. reducing the speed of detonation lowers the This method of manufacturing blasting power of the explosive. l

the drill holes were of small diameter and as the ordinary nitroglycerin and gelatinsdy- 0 but few feet in depth, and there was little or namites freeze, harden,y or congeal at temno water in the holes, peratures approximately 40 to 45 degrees However, the increased production of stone Fahrenheit.A The water in drill holes in v:1z0 has necessitated a change in the operation winter frequently is near the freezing point, k75- of quarries, and at the present time drills simand it often happens that the explosive will' ilar to those used for water wells and oil harden by contact with cold water' and will wells are used, and drilled holes from 50 feet not properly detonate. Furthermore, expoto 20() feet are common for this purpose. sure of the explosive to summer heat while Sometimes these holes are entirely Afilled with in storage in a magazine, or in transportawater. Therefore an explosive impervious tion frequently causes the nitro-glycerin'to" to water must be used, of which there is only exude, and handling while in this condition one type known at present-that known as may cause the explosiveto explode. gelatin dynamite.4 Therefore, the objects of the invention are 40 The type of pervious explosives, enerally to provide a simple, efficient, and economical called dry dynamites, may be used i? suitably blasting unit adapted to maintain the exploprotected by a water-proof container. The sives free fromwater when said unit is im- Alatter kind of explosives are cheaper to promersed in water; to construct said unit from' y duce. than gelatin dynamite and are fully materials -adapted to increase the explosive as efficient, if exploded in a dry condition. power of the explosive containedv therein; to 90 plugs in the en Y. tion ;said blasting unit provide a blasting unit with means whereby said unit is adapted to be lowered slowly in a hole; and to rovide means whereby the db ofthe casing of the said unit are unadapted to be loosened and the casin ,of said unit'is torte or fractured when said' unit is lowered into a hole. v

The invention consists of a blasting 1 1n1t comprising. a plastic ex losive contained 1n a relatively thick-Walle 'rigid container; adapted to protect the plastlc exploslve from blows and concussions during transportabeing composed of the three parts: the plastic explosive, the rigid tubular container made of combustible material, as wood pulp or other form of cellulose which material forms an essential art of the explosive formulaand tapered p ugs to form the ends of the blasting unit, the whole when assembled forming a cylinder of explosive, the outer` surface and adyacent portions of which are relatively rigid,

impermeable to water and minutely porous,

and therefore, a non-conductor of heat and cold, the inner core of the units being formed of a plastic or granular explosive.

The invention also consists in the combination of the elements, arrangement of the parts, and inthe details of the construction, as claimed.

In 'the drawings: l Fig. 1 yis a vertical section of the earth having a drilledy hole, showing the invention therein;

Fig. 2 is a transverse section of the invention taken on a line corresponding to 2--2 in Fig. 4; L

Figj3 is a bottom view of the invention; Fig. 4 is a vertical section ofthe invention,

with parts broken away, taken on a line cor-` -responding to 4-4 in Fig. 2;

Fi '5 is a vertical section showing a modi# fied orm of the invention, with parts broken' away; and e Fig. 6 is a side elevation of the same. A In the preferred construction of the 1nvention, I provide the cellulose casing or tube 1 formed from pervious combustible material, such as wood pulp, orthe like. The" tube is approximatel six inches in diameter y and twelve feet in ength, and its walls 2 `are from one-fourth to tive-eighths inch thick. v

The tube 1 is immersed in melted paraiiine which is. absorbed in the inner and outer surfaces?, and 4 ofthe walls 2 ofthe tube to a de thl dependent i1 on the temperature and quality of the para ne and the duration the tube is permitted to remain in the melted paratline.

When the temperature of the paraiine,

`which adheres to the tube' and'is absorbed into the pervious material, is lowered sutliciently to form a solid body, suitable 'explounadapted to be dis' 'sive 5; such as black powder, nitroglycerin dynamite, ammonia dynamite, chlorate explosive, `or the like, are inserted into the tube.

10v and 11 are immersed in nelted parailine for the purpose of, sealing the tube..

The tube 2, containing I the explosive 5, sealed by the plugs 8 and 9, is adapted to be inserted, and permitted to remain for a long period, into a drilled hole containing water withoutjthe water entering theY tube and vbeing-absorbed by the explosive A5. Therefore, economical explosives especially adapted to be used in a hole containing no water may be utilized in the blasting unit 1 instead of the'expensive gelatine dynamite.

vTherefore, there are certain classes of explosives adapted for quarry blasting which are desirable to use particularly because of veconomy and etlicient operation. Generally these 'latter classes have not been generally adapted and used instead of gelatin powder, because, iirst, they absorbed moisture from the air on long storage in magazines, which lowered their explosive force, and second, when exposed to direct contact with water in drill holes, their usefulness is .disadvantageously affected.

An example of an economical explosive is ammoniuml nitrate which is -very powerful when dry, and safe because it is insensitive to blows or impacts. yThis explosive was formerly used to a considerable extent, but has now come into disuse, because it readily absorbs moisture when in storage and is rendered practically useless when. lowered into water in drill holes.

Nitro-starch is an explosive which may mistire .if exposed a day to water in drill holes. This explosive is therefore impractical for use in usualpunits because in many quarries it -is customary to tire a large number of drill holes in one blast, yand frequently more than a day to load the holes. Since these holes are frequently half filled with water, the latter kind'of explosives must be protected to insure eli'icient results.

Another class of economical explosives are those of which chlorate or. perchlorate of potassium or sodium is the base. These explosives are-less subject to absorption of water in storage thanammonium explosives, but they are quickly ruined by direct exposure or contact with water.

Common black blasting powder is still an- The force of the explosion of the explosive 5 is importantly increased by utilization of the invention, because the paratline and the -combustible cellulose material, from which the tube 2 is formed, are burned simultaneousl with the explosion thereby forming ex pan 'ble gases.

To illustrate the manner in'which thelcellulose tube 2 performs the f unction'of av cars` bon carrier or vcombustile agent required 1n all explosives, the following formulas may becompa'red: A

75 lbs. potassium chlorate 7 lbs. nitro-benzene 16 lbs. sugar 2 lbs. aluminum icc ibs.

75 lbs. 7 lbs.

16 lbs. 2 lbs.

100 lbs. a

It will be observed that in the Formula A, the 16 lbs. of sugar is replaced in the formula B by 16 lbs. of cellulose tube 2, whereby the tube comprises 16%fof the explosives'of the unit. The formula B is cheaper to use, yet it is more powerful than the Formula A,

BW potassium chlorate nitro-benzene cellulose tube, paraliine aluminum Instead of( dropfping the blasting unit- 1 P into a hole in the ormation to be blasted, I provide the cable 12 having the looped end '13 received in the staple 14, which is received in the outer portion of the lower plug 9, to

. maintain the looped end in contact with the lower end 'of the blasting unit. In lowering the blasting unit into the vertical hole 15, in

the ground .16,-the lower end of the unit is per` mitted to enter vthe hole 15, and theupper end .17. of the cable 12 is gradually and slow?I ly *lowered into the hole, whereby the cable extends in contact and parallel with the outer surface of the walls of the tube 2, and 'by gravitation the unit is permitted to fall at' .alow rate of speed to the bottom of the hole.

in this manner, the lower plug' 9 is forced upwardly into the tube 2 whereby the plug is tihtened, insteadof being loosened in the tu e.

YlVloreover, since the walls of the tube 2 are relativelythick and rigid the blasting unit Vis unadapted to become distorted or fractured, whenit is lowered into a hole, as often results to a'blasting tube having thin and flexi'blewalls.

n i For the purpose of detonatin .the blasting unit 1, the detonating fuse 18 comprising a lead tube'18 containing' T. N. T. 18") has its lower end 19 secured, as by the fastener 20, to the lower plug 9 and extends upwardl in contact with the outer surface of the tu e 2,A

' 0 110 the surfaceof the ground.

In Figs. 5 and 6, l show a modiiied form I of the invention comprising the tubev 21 having its lower end 22 received in the metal cap 23. Un the bottom ofthe cap is a layer of parane 24. which prevents water from enter- A MmSKgw ing the tube and damaging the explosive 25.

An advantage of the invention 1s that vthe vexplosive in the tube is .adapted to explode instantaneously whereas the customary gelatine and nitrogiycerindynamites, packed in paper cartridges, will' not explode instantaneously, because the-paper forming the ends of vthese relatively short cartridges is folded in superimposed, layers and which are adapted to retard the speed of they wave of detonation, upon which the explosive force partly depends. This is true because the total volume of gases developed is greater in my invention and the period in which the gases are produced is considerably reduced, because the 'i ,tubes being approximately twelve feet in length, the number of the joints between the ex losive are reduced to a minimum.

till anotheradvantage of the invention is lthat a `plurality of the blasting unitsv 1 may be transported on motor trucks, or other conveyances, when lying on their sides and stocked in parallel relation with eachv other,

' without being previously packed in wooden box containers, as is necessary with other kinds of dynamites, because of the thin paper walls of cartridges or precise quantity of experature in the summer.

In the ychlorate type of explosives, it is dey l sirable to use. a nitrated oil, such as nitrobenzene as one Yof the ingredients. These oils are highly ,Volatile and volatilize and' escape from the explosive composition when subjected to long storage in magazine, particularly when packed in thin walled containers such as the ordinary paper cartridges. Therefore, an important advantage of this blasting unit is that the tube comprises thickwalled cellulose material having hermetically sealed ends which effectively prevent volatilization of nitrated oils, thus retaining their full streng'thand eiliciency during long periods of storagel; f

' It will now be apparent that l have -cleiisv vised a novel and useful structure, which embodies the features of advantage enumerated as desirable in the statementof the invention and thepabove description, and while i have, in the present instance, shown and de scribed ay preferred embodiment thereof which will give in practice satisfactory and reliable results, it is to he understood that the same -is susceptible of modicationin various particulars without departing from the .spirit or scope of the invention or sacrificing any s of its advantages. What I claim as new and desire to secure l by Letters Patent is:

' 1. A blasting unit comprising a combustible casing havmg relatively thick and rigid 1'0 side walls, explosive in said casing, detonating means to explode said unit, said casing comprising .a chemical part of the ingredients of the explosives of said unit. v

2. A blasting unit comprising a combus- 1'5 tible casing having open ends and'having relatively/'thick walls, explosive insaid casing, closure means vfor said ends, said casing and the plugs being saturated with paraiine, detonating means to explode said unit, said casing comprising approximately 16 per cent of the ingredients of the explosives of said unit and' eing a chemical part thereof.

3. A blasting unit comprising a combustible casing having relatively thick Walls, and closu'e means explosive in said casing, detonating 'means to explode said unit, said casing being a chemical part of the explosive ingredients of said unit. A

4. A blasting unit comprising acasing hav- 3g ing rigid walls, explosives -in .said casing, upper and lower plugs, respectively, in the upper and lower ends of said casing, detonat ingmeans connected with said casing, a wire cableiixed to said lower plugv` whereby said '35 unit is'adapted to be lowered into a hole with the lower end of said unit downwardly, said casing being sufficiently rigid to prevent distortion of said unit and being a chemical part of the explosive ingredients of said unit.

4@ v CLARENCE E. BEDIENT. 

